Microneedle system for applying interferon

ABSTRACT

The present invention relates to a microneedle system (MNS) for the intradermal delivery of interferon, wherein polyvinylpyrrolidone is the major constituent of a completely soluble formulation.

The present invention relates to a microneedle system (for short: MNS) for the intradermal delivery of interferon.

Interferons are endogenous messengers by way of which different cells of the immune system communicate with one another. Interferon beta-1a is produced by genetic engineering and differs only slightly from human beta interferon. The active ingredient is used for relapsing-remitting and secondary progressive forms of multiple sclerosis (MS). It is suspected that the use of beta interferon inhibits the activity of autoreactive T cells (defense cells directed against endogenous tissue), thereby delaying damage to the myelin substance, which surrounds and protects nerve fibers.

Beta interferon products presently used in the treatment of MS (such as Avonex®, Rebif®) are injected intramuscularly or subcutaneously several times a week. As a result of the self-medication of MS patients, along with the associated risks of infections and pinprick injuries, patient compliance can be significantly improved during the beta interferon therapy when a dissolving microarray is used. According to the expert opinion, a further advantage of the intradermal delivery of beta interferon may be that the active ingredient is directly released in the vicinity of immunocompetent target cells in the upper layers of the skin, which, in turn, in contrast to the parenteral delivery of the active ingredient (for example in the form of a SC infection), could result in a reduction in the frequently occurring undesirable side effects (flu-like symptoms, increase in certain liver values).

The skin consists of several layers. The outermost layer of the skin, this being the stratum corneum, has known blocking properties to prevent foreign substances from penetrating into the body and the body's own substances from exiting the body. The stratum corneum, which is a complex structure composed of compacted horny cell residues having a thickness of approximately 10 to 30 micrometers, forms a watertight membrane for this purpose to protect the body. The natural impermeability of the stratum corneum prevents most pharmaceutical active ingredients and other substances from being administered through the skin barrier as part of a transdermal delivery form. Langerhans cells are found throughout the basal granular layer of the epithelium and play an important role in the initial defense of the immune system against penetrating organisms.

Microneedle systems (MNS), which are composed of a microneedle array (MNA) and possibly further components, can use a pressure force to press the microneedles (also referred to as skin penetration elements) of the array (MNA) against the delivery site on the skin so as to penetrate the stratum corneum and thereby establish a fluid channel so that interferon can be delivered transdermally. Such microneedle arrays (MA) in microneedle systems (MS) and the production thereof are described in the prior art and are also referred to as micro(needle)array patches.

It is likewise known in the prior art that proteins, including interferon, can be delivered via MNS (for example WO2007030477A2). WO2007030477A2 provides for the use of active ingredient particles, which are moved to the tip of a perforator by centrifugation.

It is therefore the object of the present invention to enable an intradermal delivery of interferon with the aid of an MNS, containing an MNA, based on a suitable formulation.

Surprisingly, polyvinylpyrrolidone (for short: PVP) is particularly well-suited for producing a completely soluble formulation for an MNA for the intradermal delivery of interferon.

The formulation according to the invention allows sufficient strength and complete solubility, so that sufficient stability can be achieved for interferon, even without stabilizers, for the use and dissolution of the MNA, and for the absorption and distribution of the active ingredient in the organism.

In addition to the suitability of the MNA for the direct intradermal use of interferon, the formulation according to the invention likewise relates to a stable storage of the formulation according to the invention for an interferon-containing microarray, in particular at room temperature, for 3 months and longer.

The formulation according to the invention was furthermore used within the scope of an in-vitro bioassay in a human cervical cancer model cell line. It was successfully demonstrated that lysis of the human cells does not occur, despite the addition of the encephalomyocarditis virus (EMCV). The interferon, embedded into the MNA, in the formulation according to the invention has a reliable antiviral effect and exhibits potency comparable to that of the original products. As a result, the same treatment success may be assumed as that achieved with an interferon injection (SC or IM), see FIGS. 1-4.

This object is thus achieved according to the invention by a microneedle array (MNA) according to claim 1, comprising a formulation including polyvinylpyrrolidone for use in the intradermal delivery of interferon, wherein polyvinylpyrrolidone is the major constituent of the formulation.

The invention therefore likewise relates to a microneedle system comprising an MNA for use in the intradermal delivery of interferon, wherein polyvinylpyrrolidone is the major constituent of the formulation.

The invention thus comprises a product including a microneedle array, comprising a formulation including polyvinylpyrrolidone for use in the intradermal delivery of interferon, wherein polyvinylpyrrolidone is the major constituent of the formulation.

Such a product is, for example, a pharmaceutical product comprising an above-described microneedle array (MNA) for use in the intradermal delivery of interferon, and in particular for the treatment of multiple sclerosis (MS) or for interferon therapy.

A microneedle array according to the invention that has an interferon content of 0.1 μg to 200 μg, and in particular 10 μg to 100 μg per microneedle array, is particularly preferred.

According to the invention, the term “intradermal delivery” (synonym: “intracutaneous delivery”) describes the administration of interferon from the MNA into the skin and requires the microneedles to penetrate the skin.

The term “interferon” comprises all, or one or more interferons (IFN), IFN alpha, beta, gamma, interferon tau, and in particular the interferons beta-1 b, interferon beta-1a for treating multiple sclerosis (MS). Beta interferons are preferred according to the invention. Interferons are proteins or glycoproteins that exhibit an immunostimulating, and in particular an antiviral and antitumoral effect and represent endogenous cytokines.

The expression “wherein polyvinylpyrrolidone is the major constituent of the formulation” shall mean that, in addition to other adjuvants and the active ingredient interferon, polyvinylpyrrolidone is the major constituent in terms of quantity in % by weight, that is, polyvinylpyrrolidone accounts for the majority of % by weight in a composition of a completely soluble formulation.

The invention likewise relates to a method for carrying out an intradermal delivery of interferon, comprising the following steps:

-   -   a) fixing a microneedle system according to the invention to the         skin; and     -   b) a microneedle array, comprising a completely soluble         formulation including polyvinylpyrrolidone, penetrating the         skin, wherein polyvinylpyrrolidone is the major constituent of         the formulation.

Within the scope of the present invention, a microneedle system is a system comprising a device that causes the microneedle array for administering interferon onto the skin to be provided and to be intradermally delivered.

In a preferred embodiment, the microneedle system can comprise an applicator, such as a trigger device, which is electrically or mechanically controlled. For example, the applicator can comprise a plunger, which places or applies the microneedle array onto the skin, so that the microneedles penetrate the skin.

The trigger device can comprise a pump, a syringe or a spring, for example, whereby a push of the plunger can be carried out with sufficient energy. The plunger can be of any arbitrary shape and nature and is to primarily achieve that the microneedle array is provided from a first position into a second position for administering the interferon onto the skin. The applicator can furthermore comprise a push button or other trigger mechanisms.

The microneedle array can comprise a plurality of microneedles so as to be able to release interferon via the skin or into the skin of a patient, wherein the microneedle array is placed onto the skin of the patient. Each of the microneedles of the microneedle array preferably comprises an elongated shaft having two ends, the one end of the shaft forming the base of the microneedle by way of which the microneedle is attached to the planar carrier or by way of which the microneedle is integrated into the planar carrier. The end of the shaft located opposite the base preferably has a tapered shape so as to allow the microneedle to penetrate into the skin as easily as possible.

The microneedles can comprise a shaft having a round cross-section or a non-round cross-section, for example having a triangular, quadrangular or polygonal cross-section. The shaft can have one passage or multiple passages, extending from the needle base to the needle tip or approximately to the needle tip. The microneedles can be designed as (barbed) hooks, wherein one or more of these microneedles comprise one or more of such hooks. Furthermore, the microneedles can be configured in a helical shape and be rotatably disposed and thereby, when a rotating motion is applied, facilitate the penetration into the skin and effectuate anchoring in the skin (DE 103 53 629 A1), in particular at the desired penetration depth in the epidermis.

The diameter of a microneedle typically ranges between 1 μm and 1000 μm, and preferably between 10 μm and 100 μm. The length of a microneedle typically ranges between 5 μm and 6,000 μm, and in particular between 100 μm and 700 μm.

The microneedles are attached at the base thereof to a planar carrier or are integrated into a planar carrier. The microneedles are preferably disposed so as to be situated substantially perpendicularly to the surface area of the carrier. The microneedles can be arranged regularly or irregularly. An arrangement of multiple microneedles can comprise microneedles having differing cross-sectional shapes, differently dimensioned diameters and/or differing lengths. The arrangement made up of multiple microneedles can exclusively comprise hollow microneedles, for example.

The microneedle array can comprise a planar carrier, wherein the carrier essentially has a disk-shaped, plate-shaped or film-shaped basic shape. The carrier can have a round, an oval, a triangular, a quadrangular or a polygonal base surface area. The carrier can be produced from a variety of materials, such as a metal, a ceramic material, a semiconductor, an organic material, a polymer or a composite.

In a further preferred embodiment, the following substances, in addition to polyvinylpyrrolidone, are preferred in a formulation for producing the microneedles, which consist of or comprise these: disaccharide, preferably trehalose, non-ionic surfactants, preferably polysorbate (ethoxylated sorbitan fatty acid esters, such as Tween), polyalcohol, in particular glycerol (glycerin).

It is preferred that polyvinylpyrrolidone, as the major constituent, accounts for more than 35 wt. %, more than 45 wt. %, more than 55 wt. %, more than 65 wt. %, more than 75 wt. %, more than 85 wt. % in the formulation.

It is preferred that disaccharide, and in particular trehalose, as a minor constituent, accounts for more than 15 wt. %, more than 25 wt. %, more than 35 wt. % in the formulation.

TABLE 1 Concentration/dose Substance I designation Function in wt. % Beta interferon Active 0.1 μg to 200 μg per MNA ingredient Polyvinylpyrrolidone Adjuvant 0.1% to 95% (m/m) (PVP) Trehalose Adjuvant 0.1% to 45% (m/m) or up to 95% (m/m) Polysorbate Adjuvant 0.001% to 10% (m/m) Glycerol Adjuvant 0.1% to 10% (m/m) Acetate buffer Solvent 0.01% to 10% (m/m)

After the liquid formulation has been dried, for example to form a microneedle array (MNA) having a residual water content of 0.1 to 20% (m/m), a composition of the MNA is obtained that is changed accordingly by the loss of water.

The following examples and figures are provided to explain the invention in greater detail, without limiting the same.

EXAMPLES AND FIGURES

To produce the microneedles according to the invention, the known methods may be employed, such as McCrudden M T C, Alkilani A Z, McCrudden C M, McAlister E, McCarthy H O, Woolfson A D, et al. Design and physicochemical characterisation of novel dissolving polymeric microneedle arrays for transdermal delivery of high dose, low molecular weight drugs. J Control Release. 2014; 180: 71-80.

The above-described formulation was used within the scope of a preclinical in-vivo study (animal experiment model: Gottingen minipig).

FIG. 1 shows the active ingredient concentrations in the blood serum of the animals achieved after the delivery of the microarray.

Within the scope of the development of a clinical test apparatus for the beta interferon therapy, a dissolving microneedle or microarray patch (MNP) was produced and tested on the Gottingen minipig animal model.

The animal study confirms the successful use of the microarray, and the dissolution, absorption and distribution of the active ingredient substance in the animal experiment model. With this, the suitability of the active ingredient formulation was confirmed.

Even though the plasma concentration of beta interferon was lower intradermally than after SC injection, multiple sclerosis research experts are of the opinion that a higher potency could be achieved by directly releasing the active ingredient in the vicinity of the immunocompetent target cells in the upper layers of the skin. More importantly, according to experts, a lower active ingredient concentration could achieve a comparable treatment success, and considerably minimize the frequently occurring undesirable side effects. After a beta interferon injection (subcutaneous (SC) or intramuscular (IM)), the entire blood stream of the patient is usually flooded with a high concentration of cytokines within a very short time. This can be avoided with an intradermal application of the active ingredient since the active ingredient initially only reaches the interstitial liquid and the lymphatic system, and the corresponding potency, this being the initiation of immune cascades acting on the CNS, is triggered here.

FIG. 2 shows the points in time until the peak plasma level of beta interferon is reached for the intradermal delivery by way of a microarray patch compared to the SC injection.

FIG. 3 shows an antiviral beta interferon activity assay including Hep-2C cells and infectious EMCV according to Ph. Eur. 5.2.3. The beta interferon microarray (MA) exhibits a higher activity, even though the amount is absolutely identical to the standard. The formulation of the beta interferon in a semi-solid form of administration of a microarray preserves the in-vitro activity.

As a result of the elimination of stabilizers and other adjuvants in the product formulation, undesirable side effects can be precluded. Excellent stability of the active ingredient in the semi-solid, amorphous microarray structure was shown without the addition of frequently used stabilizers (such as mannitol, HSA or arginine) in the MA formulation. Moreover, stability analyses show that beta interferon formulated in microarrays can be stored at room temperature, and exhibits a specific activity comparable to other beta interferon products stored in a cool environment. It is therefore advantageously possible to store and transport beta interferon in the MA formulation without the use of a cold chain.

FIG. 4 shows the storage stability of the beta interferon microarray, and more particularly the in-vitro beta interferon activity analysis after production, after 1 month, 3 months, and after 6 months, while being stored at room temperature (21° C.) and at refrigerator temperature (5° C.). The antiviral potency of the beta interferon remains in the same log unit range as at the time of production, even after 6 months and a storage temperature of 21° C.

LEGEND FOR THE FIGURES

FIG. 1:

Averaged active ingredient concentration in the blood serum after the delivery of the microarray.

FIG. 2:

Points in time until the peak plasma level of beta interferon is reached for the intradermal delivery by way of a microarray patch compared to the SC injection.

Legend: 1 B-IFN-MA 100_g, 2 B-IFN-MA 200_g, 3 Drug substance 40_g SC., 4 Avonex 30_g S.C., 5 Rebif 44_g S.C.

FIG. 3:

Antiviral beta interferon activity assay including Hep-2C cells and infectious EMCV according to Ph. Eur. 5.2.3. Beta interferon microarray (B-IFN-MA) exhibits a higher activity, even though the amount is absolutely identical to the standard. The formulation of the beta interferon in a semi-solid form of administration of a microarray preserves the in-vitro activity.

FIG. 4:

Storage stability of the beta interferon microarray. In-vitro beta interferon activity analysis after production, after 1 month, 3 months, and after 6 months, while being stored at room temperature (21° C.) and refrigerator temperature (5° C.). The antiviral potency of the 316.4, 177.6, 171.0, 196.2, 158.8 [IU/ng] beta interferon remains in the same log unit range as at the time of production, even after 6 months and a storage temperature of 21° C. 

1-10. (canceled)
 11. A microneedle array comprising a completely soluble formulation including polyvinylpyrrolidone for use in the intradermal delivery of interferon, characterized in that polyvinylpyrrolidone is the major constituent of the formulation, and the formulation comprises disaccharide, non-ionic surfactants, polyalcohol.
 12. The microneedle array according to claim 11, wherein the polyalcohol is glycerin, or trehalose and/or polysorbate and/or glycerin.
 13. The microneedle array according to claim 11, wherein the polyvinylpyrrolidone accounts for more than 45 wt. % in the formulation.
 14. The microneedle array according to claim 11, wherein the interferon content is 0.1 μg to 200 μg per microneedle array.
 15. A product comprising the microneedle array according to claim 11 for use in the intradermal delivery of interferon.
 16. A pharmaceutical product comprising the microneedle array according to claim 11 for the treatment of multiple sclerosis or for interferon therapy.
 17. A microneedle array according to claim 11, wherein the formulation comprises up to 95 wt. % polyvinylpyrrolidone and further adjuvants and additives.
 18. A microneedle array according to claim 11, wherein the formulation comprises up to 95 wt.-% polyvinylpyrrolidone and 0.1 wt. % to 45 wt. % trehalose.
 19. A microneedle array according to claim 11, wherein the formulation comprises up to 95 wt.-% polyvinylpyrrolidone and 0.001 wt. % to 10 wt. % polysorbate.
 20. A microneedle array according to claim 11, wherein the formulation comprises up to 95 wt.-% polyvinylpyrrolidone and 0.1 wt. % to 10 wt. % glycerin.
 21. A microneedle system according to claim 11, wherein and an applicator.
 22. A microneedle system according to claim 21, wherein the applicator comprises a trigger device. 